1. Field of the Invention
The present invention relates to a video screen control card interface between the card and a computer, that provides the signals and power to drive a variety of screen modes.
2. Description of Related Art
Present computers typically have a main system that is attached to peripheral devices such as a viewing screen that displays graphic images. Graphics display subsystems are designed with a wide variety of mode standards including VGA, EGA, and CGA. Monitors which support each individual standard have different power and signal requirements. The advent of Liquid Crystal Display (LCD) screens introduce a viewing device which requires yet another set of signals and power.
Present systems typically have a control card that is attached to a motherboard to drive the screen. For a user to switch monitors, for example replacing a VGA monitor with an EGA monitor, the user must change the system software or monitor with an EGA monitor or insert a new control card. Such procedures are time consuming and add to the complexity of the computer. One possible solution is to provide a control card for each type of screen that could be used. Such a system would be heavy and bulky, and would not be desirable for a portable computer such as a laptop.
It would therefore be desirable to have a single control card that would allow the user to plug in and use various types of screens without having to change any software or hardware in the computer. Such a card would require a standard interface between the system and the card, so that a single control card can interface with a variety of screen modes. It would be particularly useful to have a standard interface that would allow the computer to plug into either a VGA monitor or LCD screen through one control card.